With the advancement in digital signal processing and communication technologies, radio and TV broadcasts are in the process of being digitalized. Digital broadcast can provide various types of additional information (e.g., news, stock, weather, traffic information, etc) as well as audio and video contents.
Due to the increase in the number of vehicles in downtown areas and highways, traffic congestions take place frequently, which results in environmental pollution. To reduce traffic congestions and environmental pollution, the use of public transportation is encouraged. To promote the use of public transportation effectively, it should be guaranteed that public transportation is convenient and predictable. In the case of bus service, a major public transportation means, it is necessary to provide information on each bus route and changes in bus travel time depending on traffic volume.
Public transportation information requires a standard format because digital public transportation information should be received and interpreted in the same way by various terminals made by different manufacturers.